Abstract: Proceeding from irreversible thermodynamics and continuum damage mechanics, an equation of remained S-N curve is derived and a accumulative fatigue damage theory is put forward which can both embody the nonlinear damage accumulation progress and reflect the difference of different cyclic dependent property. Through a great amount of comparison with test data, it is proved that the continuous accumulative damage model proposed in this paper is better than others in application scope, accuration and physical meaning, and easy to use.

Key words: 疲劳, 循环, 应力